User Manual

AT73C500
24
Electrical Characteristics
Measurement Accuracy
The accuracy measurements are based on the usage of
the AT73C500 DSP with the single-ended ADC,
AT73C501. Using the differential-ended ADC, AT73C502,
improves some of the results.
Input Conditions
When specifying measurement accuracy, it is assumed
that 80A
RMS
phase current will produce 2V
PP
full scale input
voltage to current converters. The basic current, I
B
, is sup-
posed to be 5A
RMS
.
The nominal phase voltage, U
N
, is specified to be 230V
RMS
and 2V
PP
full scale input is produced by 270V
RMS
.
Overall Accuracy, Active and Reactive Power and
Energy Measurement
Overall accuracy including errors caused by A/D-conver-
sion of current and voltage signals, calibration and calcula-
tions.
The accuracy figures are measured in nominal conditions
unless otherwise indicated in the parameter field of the
table below.
Absolute Maximum Ratings
Parameter Min Typ Max Unit
Supply Voltage V
CC
,
V
DA
, V
DDA
4.75 5.25 V
Input Voltage, Digital
-0.3
V
DD
+0.3
V
Input Voltage, Analog
-0.3
V
DA
+0.3
V
Input Voltage, CI and
VI inputs
1.25 3.75 V
Ambient Operating
Temp .
-25 +70 C
Storage Temperature -65 +150 C
Calibration Characteristics
Parameter Min Typ Max Units
Gain Calibration
Calibration Range ± 20 %
Calibration
Resolution
0.16 %
Phase Calibration
Calibration Range ± 5.625 degree
Calibration
Resolution
0.044 degree
Offset Calibration,
Active Power
Calibration Range 89.8 W
Calibration
Resolution
0.7015 W
Range,% of Full
Scale Phase Power
0.4157 %
Offset Calibration,
Reactive Power
Calibration Range 98.7 VAr
Calibration
Resolution
0.7712 VAr
Range,% of Full
Scale Phase Power
0.457 %
Parameter Nominal Value
Nominal voltage, U
N
230V, ±1%
Full-scale voltage, U
FS
270V
Full-scale current, I
FS
80A
Base current, I
B
5A
Frequency, f 50.0 Hz, ±0.3%
Power factor, PF 1
Harmonic contents of voltage less than 2%
Harmonic contents of current less than 20%
Temperature, T 23°C, ±2°C
AT73C500 master clock 3.2768 MHz